Nonlinear editing (NLE) systems are well known in the prior art, and are used in the news rooms of television broadcasting stations to assemble video clips for news stories from a variety of different electronic media files. As the name implies, NLE systems enable direct access to any frame in a digital video clip without the need to play or shuttle through adjacent footage to reach it, as was necessary with older videotape editing systems. In operation, all of the raw or source media files associated with a particular news story are imported into a source media repository. This is typically accomplished by connecting the removable memory media of a file-based digital video camera to the memory card reader of a computer. The removable memory media may take the form of solid state electronic memory devices, hard disks, or removable disks, but will hereafter be referred to as memory cards. A user inserts the memory card from the camera into the card reader of a computer and copies the file contents of the memory card into shared local or network file storage which will hereafter be referred to as a repository. The editor reviews the source media files associated with the particular news story on the viewing screen of an editing terminal and performs editing actions which cause the system to generate an Edit Decision List (EDL) which specifies which parts of which clips are connected and in what order. The final clip is created by selective electronic copying and pasting together portions of the source media files stored in the repository. This process may also include the application of various digital effects such as filters, dissolves, fades, or image overlays.
NLE systems obviate the need for the time-consuming act of mechanically cutting and splicing together the originals of the video tape or film negatives. Moreover, because the EDL is executed only by reading the source media files and not writing to them, no portion of the source media files stored in the repository is destroyed or changed as a result of the editing operation. Hence the source media files stored in the repository may be re-edited into as many different versions as desired.
Proxy-based NLE systems are also known in the prior art. Such systems were developed upon the realization that it is not necessary for the editor to view the original high definition, high-bandwidth media file in generating the EDL. Instead, a low-resolution proxy file may be used for such purposes. In operation, the low-resolution proxy file is generated and stored soon after the raw, high-resolution media file is exported into the source media repository of the system. Whereas non-proxy based NLE systems require powerful workstations to perform editing operations on full-size source video files, proxy-based systems can run on relatively inexpensive computers because of the comparatively small size of the proxy files. In proxy-based systems, the computationally intensive work of producing the proxies and the final output is usually done centrally on powerful shared servers. The ability of such proxy media files to be easily and quickly downloaded, uploaded and viewed over local networks or the broader Internet conveniently allows an editor to efficiently generate an EDL from any web-connected location via a laptop or desk top computer.